kprobes: Prohibit to probe native_get_debugreg

Since do_debug() calls get_debugreg(), native_get_debugreg() will be
called from singlestepping. This can cause an int3 infinite loop.

We can't put it in the .text.kprobes section because it is inlined,
then we blacklist its name.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
LKML-Reference: <20090827172332.8246.34194.stgit@localhost.localdomain>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index f72e96c..3267d90 100644 (file)
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -90,6 +90,7 @@ static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
  */
 static struct kprobe_blackpoint kprobe_blacklist[] = {
        {"preempt_schedule",},
+       {"native_get_debugreg",},
        {NULL}    /* Terminator */
 };